Make sure the action is right.

FIrst, are there any high spots on the frets? Stone lightly and re-profile them.

Check the forward progression of the neck. Capo at first fret, hold string down at the point the neck joins the body. If that is fret 14, measure the height of the strings above the fret at fret 7 or 8. About 0.25 mm or a bit less is right. If yours is one of those Martins with no truss rod and the progression is wrong you do have a problem and serious luthier help (not just guitar fettler help) is needed.

If you put a capo on at the first fret then measure the action (accurately, feeler guages needed) at the second. When you take the capo off that should be the height of the action at the first fret. This will probably eliminate the need for any Buzz Feiten type tricks too.

Now you can address the saddle height. Aim to get an action of abut 2.7 mm (less if you like it really low) on the bass side and a bit under 2 mm, maybe as low as 1.5 if you like it really low) on the treble side. If you have not got enough saddle height to achieve this you need a neck set.

The guitar should now be perfectly comfortable to play with 12/53s on, and really no problem with 13/56s